JP7742871B2 - Toy Systems and Cards - Google Patents

Description

The present invention relates to a toy system and cards.

There is a toy system in which cards are laid out on a flat surface such as a desk, and a moving object travels over the cards.

Patent document 1 describes how a moving object travels over a set of command cards, recognizes the patterns printed on the command cards, and obtains commands from those patterns to control the object's movements.

International Publication No. 2020/036146

Depending on the environment in which the cards were placed, the position of the card could shift when the moving object passed over it. This phenomenon made it difficult for the moving object to move stably.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide technology that enables a moving object to travel stably.

In order to solve the above problem, the toy system of the present invention includes a mobile body that can move on its own using rotating wheels, and a card on which the mobile body can move, the card including a single sheet or multiple overlapping sheets, and the coefficient of friction of the back surface of the card being greater than the coefficient of friction of the front surface of the card.

In one embodiment of the present invention, the back surface of the card may be surface-treated to have a higher coefficient of friction than the front surface of the card.

In one form of the present invention, the card may include a single sheet, and a pattern readable by the moving body and encoding information for controlling the movement of the moving body may be printed on the front surface of the sheet.

In one form of the present invention, the card includes a base sheet and two sheets that respectively form the front and back surfaces of the card, and the material of the sheet that forms the front surface of the card may be the same as the material of the sheet that forms the back surface of the card.

In one embodiment of the present invention, the sheet that forms the front surface of the card and the sheet that forms the back surface of the card may contain the same type of resin.

In one embodiment of the present invention, a visible image may be printed on the front surface of the substrate.

In one embodiment of the present invention, a pattern readable by the moving body and encoding information for controlling the movement of the moving body may be printed on the front surface of the substrate.

Furthermore, the card of the present invention is a card on which a self-propelled mobile body can run, and includes one sheet or multiple overlapping sheets, and the coefficient of friction of the back surface of the card is greater than the coefficient of friction of the front surface of the card.

In one form of the present invention, the card may be printed with a pattern that is read by the mobile object and that encodes information that controls the movement of the mobile object.

This invention allows the moving body to travel stably over the card.

1 is a diagram illustrating an example of a toy system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a hardware configuration of a toy system. FIG. 2 is a diagram showing an example of a moving object as viewed from below. FIG. 2 is a schematic cross-sectional view of a card. FIG. 10 is a diagram illustrating an example of a moving object running on a card. FIG. 10 is a diagram illustrating an example of an image printed on a card. FIG. 10 is a diagram illustrating an example of control of a moving object by a card. 10 is a flowchart illustrating an example of processing by a moving body. 10 is a flowchart illustrating an example of processing by a moving body.

The following describes an embodiment of the present invention with reference to the drawings. Components that have the same function are designated by the same reference numerals, and their description will be omitted.

Figure 1 shows an example of a toy system according to an embodiment of the present invention. The toy system according to the present invention includes at least a moving body 20 and a plurality of cards 30. The moving body 20 has a cube-like outer shape with chamfered corners. The top surface also has a number of protrusions that allow other toys to be attached.

At least some of the multiple cards 30 are placed by the user anywhere on a flat surface (for example, on a desk or floor). When the mobile object 20 travels over any of the cards 30, it reads the image and performs an action according to the instructions indicated by the image.

The multiple cards 30 are classified into multiple card types, and are printed with an image in which information corresponding to the card type is encoded. This information controls the operation of the mobile object 20, and is classified into operation instructions and setting instructions. Cards 30 on which images in which operation instructions are encoded are printed are called operation instruction cards.

The multiple cards 30 include multiple action instruction cards, each of which has an image printed on it that indicates an action instruction for the moving object 20. Each of the multiple action instruction cards has an encoded image printed on it that indicates one of multiple action instructions for the moving object 20. The type of action instruction corresponds one-to-one to the card type, and decoding the card type corresponds to decoding the action instruction.

Operational instructions are also classified into multiple types (groups). These types include state change, action, and force. The state change group is a group consisting of instructions that change the operation of the mobile object 20 (e.g., the driving state). Operational instructions belonging to the state change group are further classified into multiple subgroups. The multiple subgroups include a steering subgroup, a speed subgroup, and a braking subgroup. Each subgroup has a driving parameter. The steering subgroup includes an instruction to turn the steering wheel to the right or left, and an instruction to turn the steering wheel to go straight. The speed subgroup includes an instruction to set the speed driving parameter to a specified value. The specified value may be one of multiple predetermined candidate values (e.g., slow, fast, very fast). The braking subgroup includes a braking instruction to continuously reduce the speed. Note that operation instructions may be labeled into multiple subgroups, such as a speed subgroup and a steering subgroup.

The action-type instructions are a group consisting mainly of instructions that cause the mobile object 20 to perform a predetermined action. An action-type instruction may resume the previous action after the action is performed. Note that even an action-type instruction may result in a change in the running state. The force-type instructions are a group consisting of instructions that cause the mobile object 20 to immediately stop.

Figure 2 shows an example of the hardware configuration of a toy system. The mobile object 20 included in the toy system includes a processor 21, storage 22, a communication unit 23, a camera 24, two motors 25, and a speaker 26.

The processor 21 operates according to a program stored in the storage 22, and controls the communication unit 23, camera 24, motor 25, speaker 26, etc. The program may be provided from another computer via communication via the communication unit 23. The program may be stored in a computer-readable storage medium such as a flash memory or optical disk and provided to the other computer. The number of processors 21 may be one or more.

Storage 22 is composed of DRAM, non-volatile memory, etc. Storage 22 stores the above programs. Storage 22 also stores information and calculation results input from processor 21, communication unit 23, etc.

The communication unit 23 is composed of a radio frequency circuit, an antenna, etc. for communicating with other devices. The communication unit 23 has the function of communicating with other devices (e.g., computers) according to, for example, the Bluetooth (registered trademark) protocol or a wireless LAN protocol. Under the control of the processor 21, the communication unit 23 inputs information received from other devices into the processor 21 or storage 22, and transmits information to other devices. Note that the communication unit 23 may also communicate with other devices via a wired network.

The camera 24 is positioned to capture images below the moving object 20, and repeatedly captures images below the moving object 20. When the moving object 20 travels over the card 30, the camera 24 captures an image of the pattern 71 (see Figure 4) printed on the card 30. In this embodiment, the card 30 is printed with the pattern 71, which can be recognized in the infrared frequency range, and the camera 24 captures an image of this infrared light. In addition to the pattern 71, the card 30 is also printed with an image that can be recognized in visible light.

The motor 25 is a so-called servo motor, whose rotation direction, amount of rotation, and rotation speed are controlled by the processor 21.

The speaker 26 outputs audio based on the control of the processor 21, etc.

Figure 3 is a bottom view of an example of the mobile body 20. The mobile body 20 further includes a switch 222, a power switch 223, and two wheels 254. One motor 25 is assigned to each of the two wheels 254, and the motor 25 drives the assigned wheel 254. The drive mechanism including the motor 25 and the wheels 254 constitute a traveling device that causes the mobile body 20 to travel.

The structure of card 30 is described below. Figure 4 is a schematic cross-sectional view of card 30. Card 30 has a strength that makes it difficult to bend. The coefficient of friction of the back surface of card 30 is greater than the coefficient of friction of the front surface of card 30.

The card 30 includes multiple sheets stacked one on top of the other. The multiple sheets include a base material 35, a front sheet 36, and a back sheet 37. The front sheet 36 forms the front surface of the card 30, and the back sheet 37 forms the back surface of the card 30. The multiple sheets are stacked in the order of front sheet 36, base material 35, and back sheet 37 from top to bottom. A printed layer 39 exists between the base material 35 and the front sheet 36. An image recognizable with visible light and a pattern 71 recognizable with infrared light are printed on the front surface of the base material 35 as the printed layer 39. The thickness of the card 30 is, for example, 0.45 mm or less. The card 30 may have a thickness that allows the moving object 20 to ride over it and is difficult to bend.

The substrate 35 may be made of resin or paper. More specifically, the material of the substrate 35 may be any of paper, polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), and polyvinyl chloride (PVC). The material of the substrate 35 may be selected from the above materials taking into consideration rigidity, durability, price, smoothness (resistance to warping), and heat resistance.

The front sheet 36 and the back sheet 37 are films that are attached to the base material 35. The front sheet 36 and the back sheet 37 may be formed by laminating a film onto the base material 35, or by coating. The material of the front sheet 36 may be the same as the material of the back sheet 37, and specifically, they may contain the same type of resin. Specifically, the material of the front sheet 36 and the back sheet 37 may be either PP or PET. By using the same material for the front sheet 36 and the back sheet 37, warping due to temperature changes, etc. can be prevented.

Here, the back surface of card 30, i.e., back sheet 37, is surface-treated to have a higher coefficient of friction than the front surface of card 30. For example, the front surface of card 30 may be matte-finished, and the back surface may be coated with a material with a high coefficient of friction. Alternatively, the back surface may be matte-finished, and the front surface may be untreated. The matte finish may be achieved by attaching a film with a rough surface (e.g., a matte film) to base material 35 as front sheet 36 or back sheet 37, or by applying a material such as resin, varnish, or silicone-based ink to front sheet 36 or back sheet 37. A velvet PP finish may be used instead of the matte finish or material application.

These surface treatments make it possible to increase the coefficient of friction even without applying an adhesive for a sticker to the back surface of the card 30. Instead of surface treatment using the front sheet 36 or back sheet 37, the coefficient of friction of the back surface of the card 30 may be made higher than that of the front surface by printing or applying a material to the base material 35. For example, the surface of the base material 35 may be printed with a printing layer 39 and coated with a protective layer (varnish) (printing alone may be sufficient), and then coated with a resin or silicone-based ink with a higher coefficient of friction. In this case, the card 30 may be composed of a single sheet of the base material 35.

Figure 5 is a diagram illustrating an example of a moving object 20 moving over a card 30. In Figure 5, the card 30 is placed on a desk. When the moving object 20 moves over the card 30, the friction between the rotating wheels 254 and the card 30 transmits a force to the card 30 in the opposite direction (rearward) to the moving object's 20 direction of travel. If the friction between the card 30 and the desk is insufficient, the card 30 will slip backward. By increasing the coefficient of friction on the back side of the card 30, the limit of static friction between the card 30 and the desk is increased, making it possible to prevent the card 30 from slipping. Furthermore, by decreasing the coefficient of friction on the front side of the card 30, it is possible to reduce the possibility of excessive force being transmitted to the card 30 and causing it to slip out of position when the moving object 20 makes a sudden movement.

Next, the planar structure of the printing layer 39 will be described. Figure 6 is a diagram illustrating an example of an image printed on the card 30. The front surface of the card 30 includes an internal area 31 surrounded by a dashed line in Figure 6, and a peripheral area 32 outside the dashed line and surrounding the internal area 31. A plurality of patterns 71 are printed in a matrix on the front side of the card 30 (strictly speaking, the front side of the base material 35). Each pattern 71 is an image of a predetermined size, for example, 0.2 mm square. The pattern 71 is an image in which information for controlling the operation of the moving object 20 is encoded. This information also indicates the card type.

The size of each pattern 71 is smaller than the size of the moving object 20. In Figure 4, the pattern 71 is depicted on a portion of the card 30, but in reality, it is arranged so that it fills the entire surface of the card 30. For ease of explanation, the image "Sound," which can be recognized with visible light, is depicted with a dashed line.

In the internal area 31, a plurality of identification patterns 72 are arranged within the pattern 71, each of which indicates the card type to which the card 30 belongs. The identification pattern 72 is an image in which card type information is encoded, and the image of the identification pattern 72 varies depending on the card type. The plurality of identification patterns 72 are arranged in a matrix within the internal area 31. For the same card 30, the plurality of identification patterns 72 may have the same image. Note that the internal area 31 does not have to be rectangular, and patterns 71 that extend beyond the internal area 31 become peripheral patterns 73, described below, rather than identification patterns 72. Furthermore, to ensure that a mobile object 20 traveling within the internal area 31 can always recognize the identification patterns 72, for example, 3 x 3 or more identification patterns 72 are arranged within the internal area 31. The identification patterns 72 do not necessarily have to be arranged in a matrix; they may be arranged in concentric circles, for example.

The peripheral area 32 is arranged on the periphery of the front surface of the card 30. Multiple peripheral patterns 73 are arranged in the peripheral area 32, surrounding the internal area 31 in which the multiple identification patterns 72 are arranged. Looking at it from another perspective, the identification patterns 72 indicating any of the card types are not printed in the peripheral area 32. The peripheral pattern 73 is a pattern 71 that does not indicate any of the multiple card types, and is an image in which peripheral information different from the information indicating the card type is encoded. In this embodiment, the peripheral information is a fixed value regardless of the card type, but it does not necessarily have to be a fixed value. The multiple peripheral patterns 73 need only be arranged so that they can be read by a moving object 20 traveling from the internal area 31 toward the outside of the card 30, and do not necessarily have to be arranged in a matrix. The width of the peripheral area 32 may, for example, be more than twice the size of the pattern 71.

Although the dashed dotted line is not actually printed, it is clear that the boundary between the internal region 31 and the peripheral region 32 exists between the adjacent identification pattern 72 and peripheral pattern 73, making it easy to confirm the existence of the internal region 31 and the peripheral region 32. The pattern 71 does not need to be printed in the peripheral region 32.

When the moving object 20 travels over the card 30, the camera 24 of the moving object 20 captures an image of the pattern 71 printed on the card 30, and the processor 21 decodes the image to obtain information. For example, the moving object 20 obtains operation instructions from an identification pattern 72 printed on the operation instruction card. The moving object 20 obtains peripheral information from a peripheral pattern 73. Here, the moving object 20 detects the direction of the moving object 20 (e.g., angle A from a reference direction) by detecting the inclination of the pattern 71 in the image captured by the camera 24. The decoding may be performed by another computer included in the toy system and connected to the moving object 20 for communication. As the moving object 20 passes over the card 30, the pattern 71, which is printed in different positions as time passes, is read.

Next, control of the moving object 20 using cards 30 will be described. Figure 7 is a diagram illustrating an example of control of the moving object 20 using action instruction cards. In the example of Figure 7, the action instruction cards arranged are a "Fast" card 30b and an arrow card 30h indicating the direction of travel. In the example of Figure 7, the moving object 20 first reads pattern 71 on card 30b, updates the parameters of the speed subgroup to the specified (faster) speed, and moves straight ahead at that speed. Then, it reads pattern 71 on card 30h, and performs an action to turn (change direction) so that the direction indicated by pattern 71 and the moving direction of the moving object 20 form a specified angle (the moving object 20 faces the direction of the arrow). Once the change in direction is complete, the moving object 20 moves straight ahead in the direction of travel.

As shown in the example of Figure 7, the operation of the mobile object 20 is controlled by the card 30. In the example of Figure 7, for example, driving parameters are changed in response to the operational instructions of the card 30, and the mobile object 20 then moves in accordance with those operational instructions until it reaches the next card 30. This makes the reading of the card 30 and the resulting operation interactive, allowing the user to experience more intuitive and easier programming.

Next, the processing for realizing the above operations will be described in more detail. Figures 8 and 9 are flowcharts showing an example of the processing of the mobile object 20. The processing shown in Figures 8 and 9 is realized by the processor 21 of the mobile object 20 executing a program stored in the storage 22. Furthermore, some of the processing may be realized by the processor 21 of another computer included in the toy system that is communicatively connected to the mobile object 20. The processing shown in Figures 8 and 9 is repeatedly executed periodically (for example, every 0.1 seconds).

First, processor 21 acquires an image captured by camera 24 of mobile object 20 (S101). Processor 21 determines whether information can be decoded from the acquired image (S102). This process determines whether pattern 71 is present in the acquired image. If the information cannot be decoded (N in S102), processor 21 sets the same card flag to OFF and terminates the process shown in Figures 8 and 9. On the other hand, if the information can be decoded (Y in S102), processor 21 determines whether the decoded information is peripheral information (S104). This determination may be made based on whether the decoded information is within a range of values indicating the card type. If the decoded information is peripheral information (Y in S104), processor 21 sets the same card flag to OFF and terminates the process shown in Figures 8 and 9. On the other hand, if the decoded information is not peripheral information (N in S104), processor 21 checks whether the same instruction as the previous one has been decoded (S105). If the same instruction as the previous one has not been decoded (N in S105), S106 is skipped and the processing from S107 onwards is executed. If the same instruction as the previous one has been decoded (Y in S105), processor 21 determines whether the same card flag is set to ON (S106).

If the same card flag is set to ON (Y in S106), processor 21 ends the processing shown in Figures 8 and 9. On the other hand, if the same card flag is set to OFF (N in S106), processor 21 sets the same card flag to ON (S107). Processor 21 also obtains an instruction (here, an operation instruction) from the decoded card type, and obtains the angle A of moving body 20 relative to card 30 (S108). Then, as shown in S111 and onwards, processor 21 executes processing to operate moving body 20 in accordance with that instruction (processing to control the running device, speaker 26, etc.).

The processes of S102 to S104 and S106 to S108 detect whether card type information has been obtained from the same card 30 as previously, and if card type information has been obtained from the same card 30, new control based on the instructions indicated by the card type is not executed. Furthermore, if card type information has been obtained from a new card 30 through these processes, new control based on the instructions indicated by that card type is executed. The process of S105 is executed when the mobile object 20 is moved by hand and the identification patterns 72 of two different types of cards 30 are forcibly read.

For example, if two cards 30 are arranged so that they partially overlap, and the mobile object 20 moves across the boundary between them, the patterns 71 printed on the two cards 30 are read consecutively. However, after the internal area 31 of the first card 30 is read, the peripheral area 32 of one of the cards 30 is read, and then the internal area 31 of the second card is read. The same card flag that was turned ON (see S106) when the internal area 31 of the first card 30 was read is turned OFF when the peripheral area 32 is read (see S104, S103), and the mobile object 20 is controlled by the operation instructions read from the internal area 31 of the second card 30. In this way, when the identification pattern 72 is photographed after the peripheral pattern 73 is photographed by the camera 24, the processor 21 controls the operation of the mobile object 20 based on the photographed identification pattern 72. On the other hand, if the same identification pattern 72 as the previous one is captured by the camera 24, the operation of the mobile object 20 is not controlled by reading that identification pattern 72. In this way, reading from a new card 30 can be detected by the surrounding area 32.

Instead of using the same card flag, information decoded from the pattern 71 captured by the camera 24 in the previous process may be stored, and if it is not the same as the information decoded from the pattern 71 captured this time, processing may be executed to control the operation of the mobile object 20 according to the decoded card type. In this case, if information cannot be decoded from the image, dummy information may be stored instead of the decoded information, allowing for the case where the surrounding pattern 73 cannot be read for some reason.

Returning to the explanation of the processing in Figures 8 and 9, when the processing in S107 is executed, the processor 21 determines whether the acquired operation instruction belongs to a state change group (S111). If the acquired operation instruction belongs to a state change group (Y in S111), the processor 21 updates the driving parameters in accordance with the operation instruction (S112).

More specifically, processor 21 updates the driving parameters of the subgroup to which the action instruction belongs to the value indicated by that action instruction. If the action instruction belongs to the speed subgroup, processor 21 sets the speed parameter to a value corresponding to the action instruction. If the action instruction belongs to the steering subgroup, processor 21 updates the steering state parameter to the value indicated by the action instruction (for example, right, left, or straight). If the action instruction belongs to the braking subgroup, processor 21 updates the brake parameter to the braking state (or no-brake state).

If an action instruction belongs to multiple subgroups, processor 21 updates the driving parameters of each of the multiple subgroups to the value indicated by that action instruction. For example, if an action instruction belongs to a speed subgroup and a steering subgroup, processor 21 sets the speed parameter to a value corresponding to the action instruction and updates the steering state parameter to the value indicated by the action instruction. In this case, there may be multiple action instructions that correspond one-to-one to each combination of candidate values for the speed parameter (e.g., slow, fast, very fast) and candidate values for the steering state parameter (e.g., right, left, straight). There may be a card 30 that corresponds one-to-one to each of the multiple action instructions.

On the other hand, if the acquired operation instruction does not belong to the state change system (N in S111), the processor 21 determines whether the acquired operation instruction indicates an instruction to stop the moving body 20 (S113). If the operation instruction indicates an instruction to stop the moving body 20 (Y in S113), the processor 21 ends the travel processing and stops the moving body 20 (S114).

On the other hand, if the action instruction does not indicate an instruction to stop the moving object 20 (N in S113), the processor 21 determines whether the acquired action instruction belongs to an action group (S115). If the action instruction does not belong to an action group (N in S115), the processing of Figures 8 and 9 ends. If the action instruction belongs to an action group (Y in S115), the processor 21 controls the traveling device to perform an action according to the action instruction (S116).

For action-based movement instructions, particularly those that cause the moving object 20 to turn in a specified direction, such as card 30h, the processor 21 determines the direction and amount of rotation of the left and right motors 25 based on the angle read from card 30. The direction and amount of rotation are determined so that the orientation of the moving object 20 after rotation will be in a predetermined direction (for example, the direction of the arrow on card 30h) relative to the card 30 from which the angle was read. The processor 21 then rotates the left and right motors 25 in the determined direction and amount of rotation. When the rotation ends, running is resumed according to the running parameters.

For action-based operation instructions that cause the mobile object 20 to perform a typical operation such as a rotation (spin), serpentine driving, or audio output, the processor 21 first acquires time-series control information that is associated with the action-based operation instruction and recorded in the storage 22. Based on the time-series control information, the processor 21 controls at least one of the motor 25 and the speaker 26, causing the mobile object 20 to perform the typical operation. When this time-series control ends, driving based on the driving parameters is resumed.

Next, we will briefly explain the driving process. In the driving process, the processor 21 executes a program stored in the storage 22 to control the driving device (e.g., the motor 25) based on driving parameters. Some of the processing may be performed by the processor 21 of another computer included in the toy system that is communicatively connected to the mobile object 20. In the driving process, the following processing is periodically executed.

When the brake state is set as one of the driving parameters, the processor 21 continuously reduces the speed of the mobile object 20 by subtracting a predetermined value from the speed value stored as a driving parameter. If the subtracted speed value is 0, the processor 21 stops the mobile object 20 and transitions the state of the mobile object 20 to a stopped state. Furthermore, the processor 21 determines the rotation speed of the left and right wheels 254 based on the speed value and the steering state parameter, and controls the rotation of the left and right motors 25 based on the determined rotation speed. The difference in the rotation speed between the left and right can cause the mobile object to continuously turn left and right. By using the driving parameters, the mobile object can operate without problems even if operation instructions read from the same card 30 are ignored, and accurate control can be achieved even when multiple cards are used by utilizing the surrounding area 32.

20 Mobile body, 21 Processor, 22 Storage, 23 Communication unit, 24 Camera, 25 Motor, 26 Speaker, 222 Switch, 223 Power switch, 254 Wheels, 30, 30b, 30h Card, 31 Internal area, 32 Peripheral area, 35 Base material, 36 Front sheet, 37 Back sheet, 39 Printing layer, 71 Pattern, 72 Identification pattern, 73 Peripheral pattern.

Claims (9)

a mobile body that can move by itself using rotating wheels;
a card that can be placed on a desk with its backside adjacent to the table, and the moving body can travel on its front side ;
Including,
The card may comprise one sheet or multiple sheets stacked together;
the coefficient of friction of the back surface of the card is greater than the coefficient of friction of the front surface of the card;
A printed layer having a higher coefficient of friction than the front surface is provided on the back surface of the card, or the back surface of the card is matte-finished.
Toy system. 10. The toy system of claim 1,
the back surface of the card is matt-finished with any one of resin, varnish, and silicone-based ink;
Toy system. 3. The toy system according to claim 2,
the card includes one sheet;
a pattern readable by the moving body and encoding information for controlling the movement of the moving body, printed on the front side of the sheet;
Toy system. 3. The toy system according to claim 1 or 2,
The card includes a base sheet and two sheets that respectively form the front and back surfaces of the card,
The material of the sheet that forms the front surface of the card is the same as the material of the sheet that forms the back surface of the card.
Toy system. 5. The toy system according to claim 4,
the sheet constituting the front surface of the card and the sheet constituting the back surface of the card contain the same type of resin;
Toy system. 5. The toy system according to claim 4,
A visible image is printed on the front surface of the substrate.
Toy system. 5. The toy system according to claim 4,
a pattern readable by the movable body and encoding information for controlling the movement of the movable body, printed on the front surface of the substrate;
Toy system. A card that can be placed on a desk with its back side adjacent to the desk, and a self-propelled mobile object can run on its front side ,
It may comprise one sheet or multiple sheets stacked together,
the coefficient of friction of the back surface of the card is greater than the coefficient of friction of the front surface of the card;
A printed layer having a higher coefficient of friction than the front surface is provided on the back surface of the card, or the back surface of the card is matte-finished.
card. 9. The card of claim 8,
a pattern that is read by the mobile object and that encodes information for controlling the movement of the mobile object is printed on the card;
card.